I have no direct experience with a 261/T5 setup. However, my 235/sm420 never feels underpowered, and I’d assume that your combination of more cubes and more gears will be even better. Put some real thought into your rear end ratio….that will be key.
If it were me, I’d lean toward keeping simple. Stock intake with a working heat flap. Stock exhaust. Single carb but definitely not a Rochester. I’d look for an appropriately-sized Carter YF or Zenith.
There has been some recent discussion around here about various HEI setups. Easily done, if you’re into that. I like the way the points distributor looks and have no complaints about the way mine performs.
